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package Filter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;


@WebFilter({"/cs","/cas","/Buy.jsp","/discuss.jsp"})
public class MyFilter implements Filter{

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req=(HttpServletRequest)request;
        HttpServletResponse resp=(HttpServletResponse)response;
        HttpSession session=req.getSession();
        resp.setContentType("text/html;charset=utf-8");
        if(session.getAttribute("isLogin")!=null){
            chain.doFilter(request, response);
        }
        else{
             resp.getWriter().println("<script language='javascript'>alert('请先登录！');window.location.href='Login.jsp';</script>");
        }
    }

    @Override
    public void destroy() {
        
    }
    
}
